Organic Light-Emitting Diode (OLED) of each pixel in an AMOLED panel is capable of emitting light when it is driven by a current generated by a driving Thin Film Transistor (TFT) in a saturated state. That is, the OLED is driven by the current to emit light. FIG. 1 is a principal diagram showing a pixel structure of an existing basic current mode AMOLED panel. As shown in FIG. 1, the pixel structure of the existing basic current mode AMOLED panel includes an OLED, a T1, a T2, a T3, a T4 and a storage capacitor Cst, wherein the T1 is a driving Thin Film Transistor, the T2, T3 and T4 are controlling Thin Film Transistors, a gate of the T2 and a gate of the T3 are connected to a control line for outputting a control signal CN1, a gate of the T4 is connected to a control line for outputting a control signal CN2. In the pixel structure of the existing basic current mode AMOLED panel, a driving current Idata is externally applied so as to set a voltage on the storage capacitor Cst, and then generates a driving current Ioled for driving OELD to emit light. In the pixel structure of the existing basic current mode AMOLED panel, the Ioled is equal to the Idata, but the Ioled is small since it has to be in a operation current range of the OLED, and in turn the Idata is also small. However, the storage capacitor Cst usually has a large capacitance, so a charging speed thereof is slow when the Idata is small, thus a charging time is especially long under a low gray level, which is not suitable for AMOLED panel display with high solution and high refresh frequency.